Proportioning valve vs No valve

[STOCKISH]

In process of my 81 C10 rebuild and converting to manual brakes (Wilwood master cylinder) and installing Slosh Tubz firewall filler panels to clean up the firewall as much as possible. I have a couple questions. What bore master cylinder are people using when going to manual brakes. Currently a disc/drum setup. Also, I have seen some people using a proportioning valve and some people not. Do I need to run one? If so can I use the factory one or need to find one that was designed for manual brakes. Thanks for any feedback.

Those of you running manual brakes, can you post pics of how you ran your brake lines, Id like to do away with the spiral of brake line @ the master cylinder.

[sweetk30]

the factory valve is a TEE for the front and restricter for the rear be it a fixed ratio . then if a line pops or looses fluid the bias valve inside moves and trips the switch for the light in the dash .

i run this style my self and like it . you dont get a switch for the dash light but i dont care my self .

wilwood https://www.summitracing.com/parts/wil-260-11179

summit looks identical https://www.summitracing.com/parts/sum-g3906

these give you the TEE for the front and adjustable rear to dial it in were you like the bias .

or do the line lock in the front for the TEE and line lock and 1 of these plumbed in the rear feed .

wilwood https://www.summitracing.com/parts/wil-260-8419

summit looks the same as wilwood https://www.summitracing.com/parts/sum-g3905

the spiral of brake line is for body to frame flex . if the line is to rigid it will shake and brake its self much faster . i have seen lots of late model stuff with a much nicer section of braided s.s. flex line thats straight in there from the master and would be a cleaner look . you would have to junk yard hunt for that tho and make your own line combo from there .

[mongocanfly]

Better use a disc/drum prop valve like sweetk showed..
And you need a disc/drum master cyl as well...
If you dont already have one pol can hook you up with what you need
.
Heres how I did my lines to eliminate the moonshine still coils..
-an fittings and ss braid, lines

[MikeB]

For manual brakes the factory used a master cylinder bore of just under 1 inch (25 mm, I think). At least that was true for the 82 model C10.

If I were going power to manual, I'd probably do 15/16". And if you plumb in a manual prop valve, you can fine tune the system so the rears don't lock up prematurely.

BTW, for me this would be the ultimate kit. I had the 7/8" version on a 55 Chevy car with entry-level Wilwood front brakes and 9"x 2" rear drums. Worked great! Move down the page to see the 15/16" and 7/8" part numbers.https://www.wilwood.com/MasterCylind...%20and%20Valve